
Amiens is the forest court's resident singer - his songs punctuate the pastoral scenes with music, providing atmosphere and a gentle comic foil to Jaques's insistence on finding melancholy in everything, including cheerful songs.
Amiens is a lord attending Duke Senior in exile, distinguished chiefly by his singing - he provides the forest's musical texture, performing 'Under the greenwood tree' and later 'Blow, blow, thou winter wind' at moments when the play wants to pause its plot and let the pastoral mood simply exist for a scene.
His exchanges with Jaques are gently comic in their mismatch: Jaques praises Amiens's singing while insisting he wants more of it precisely because it makes him more melancholy, a request Amiens finds bewildering but obliges anyway, adding his own verse to Jaques's cynical commentary on the song's meaning.
Amiens's function throughout is atmospheric rather than dramatic - he does not drive any plot thread, but his songs mark the forest as a place where feeling can be expressed communally and musically rather than only through the private plotting and courtship that occupies the other characters, and his presence rounds out Duke Senior's court with a note of genuine, uncomplicated pleasure.
Amiens is motivated by a straightforward love of music and loyal service to Duke Senior, content to provide the forest company's entertainment without seeking any larger role in its plots.
Amiens is defined almost entirely by his singing and his easy good nature, offering the forest court a note of simple pleasure that stands in gentle contrast to Jaques's determined gloom.